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1 | /* Helpers for initial module or kernel cmdline parsing | |
2 | Copyright (C) 2001 Rusty Russell. | |
3 | ||
4 | This program is free software; you can redistribute it and/or modify | |
5 | it under the terms of the GNU General Public License as published by | |
6 | the Free Software Foundation; either version 2 of the License, or | |
7 | (at your option) any later version. | |
8 | ||
9 | This program is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | GNU General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
15 | along with this program; if not, write to the Free Software | |
16 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
17 | */ | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/string.h> | |
20 | #include <linux/errno.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/moduleparam.h> | |
23 | #include <linux/device.h> | |
24 | #include <linux/err.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/ctype.h> | |
27 | ||
28 | #ifdef CONFIG_SYSFS | |
29 | /* Protects all built-in parameters, modules use their own param_lock */ | |
30 | static DEFINE_MUTEX(param_lock); | |
31 | ||
32 | /* Use the module's mutex, or if built-in use the built-in mutex */ | |
33 | #ifdef CONFIG_MODULES | |
34 | #define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock) | |
35 | #else | |
36 | #define KPARAM_MUTEX(mod) (¶m_lock) | |
37 | #endif | |
38 | ||
39 | static inline void check_kparam_locked(struct module *mod) | |
40 | { | |
41 | BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod))); | |
42 | } | |
43 | #else | |
44 | static inline void check_kparam_locked(struct module *mod) | |
45 | { | |
46 | } | |
47 | #endif /* !CONFIG_SYSFS */ | |
48 | ||
49 | /* This just allows us to keep track of which parameters are kmalloced. */ | |
50 | struct kmalloced_param { | |
51 | struct list_head list; | |
52 | char val[]; | |
53 | }; | |
54 | static LIST_HEAD(kmalloced_params); | |
55 | static DEFINE_SPINLOCK(kmalloced_params_lock); | |
56 | ||
57 | static void *kmalloc_parameter(unsigned int size) | |
58 | { | |
59 | struct kmalloced_param *p; | |
60 | ||
61 | p = kmalloc(sizeof(*p) + size, GFP_KERNEL); | |
62 | if (!p) | |
63 | return NULL; | |
64 | ||
65 | spin_lock(&kmalloced_params_lock); | |
66 | list_add(&p->list, &kmalloced_params); | |
67 | spin_unlock(&kmalloced_params_lock); | |
68 | ||
69 | return p->val; | |
70 | } | |
71 | ||
72 | /* Does nothing if parameter wasn't kmalloced above. */ | |
73 | static void maybe_kfree_parameter(void *param) | |
74 | { | |
75 | struct kmalloced_param *p; | |
76 | ||
77 | spin_lock(&kmalloced_params_lock); | |
78 | list_for_each_entry(p, &kmalloced_params, list) { | |
79 | if (p->val == param) { | |
80 | list_del(&p->list); | |
81 | kfree(p); | |
82 | break; | |
83 | } | |
84 | } | |
85 | spin_unlock(&kmalloced_params_lock); | |
86 | } | |
87 | ||
88 | static char dash2underscore(char c) | |
89 | { | |
90 | if (c == '-') | |
91 | return '_'; | |
92 | return c; | |
93 | } | |
94 | ||
95 | bool parameqn(const char *a, const char *b, size_t n) | |
96 | { | |
97 | size_t i; | |
98 | ||
99 | for (i = 0; i < n; i++) { | |
100 | if (dash2underscore(a[i]) != dash2underscore(b[i])) | |
101 | return false; | |
102 | } | |
103 | return true; | |
104 | } | |
105 | ||
106 | bool parameq(const char *a, const char *b) | |
107 | { | |
108 | return parameqn(a, b, strlen(a)+1); | |
109 | } | |
110 | ||
111 | static void param_check_unsafe(const struct kernel_param *kp) | |
112 | { | |
113 | if (kp->flags & KERNEL_PARAM_FL_UNSAFE) { | |
114 | pr_warn("Setting dangerous option %s - tainting kernel\n", | |
115 | kp->name); | |
116 | add_taint(TAINT_USER, LOCKDEP_STILL_OK); | |
117 | } | |
118 | } | |
119 | ||
120 | static int parse_one(char *param, | |
121 | char *val, | |
122 | const char *doing, | |
123 | const struct kernel_param *params, | |
124 | unsigned num_params, | |
125 | s16 min_level, | |
126 | s16 max_level, | |
127 | void *arg, | |
128 | int (*handle_unknown)(char *param, char *val, | |
129 | const char *doing, void *arg)) | |
130 | { | |
131 | unsigned int i; | |
132 | int err; | |
133 | ||
134 | /* Find parameter */ | |
135 | for (i = 0; i < num_params; i++) { | |
136 | if (parameq(param, params[i].name)) { | |
137 | if (params[i].level < min_level | |
138 | || params[i].level > max_level) | |
139 | return 0; | |
140 | /* No one handled NULL, so do it here. */ | |
141 | if (!val && | |
142 | !(params[i].ops->flags & KERNEL_PARAM_OPS_FL_NOARG)) | |
143 | return -EINVAL; | |
144 | pr_debug("handling %s with %p\n", param, | |
145 | params[i].ops->set); | |
146 | kernel_param_lock(params[i].mod); | |
147 | param_check_unsafe(¶ms[i]); | |
148 | err = params[i].ops->set(val, ¶ms[i]); | |
149 | kernel_param_unlock(params[i].mod); | |
150 | return err; | |
151 | } | |
152 | } | |
153 | ||
154 | if (handle_unknown) { | |
155 | pr_debug("doing %s: %s='%s'\n", doing, param, val); | |
156 | return handle_unknown(param, val, doing, arg); | |
157 | } | |
158 | ||
159 | pr_debug("Unknown argument '%s'\n", param); | |
160 | return -ENOENT; | |
161 | } | |
162 | ||
163 | /* You can use " around spaces, but can't escape ". */ | |
164 | /* Hyphens and underscores equivalent in parameter names. */ | |
165 | static char *next_arg(char *args, char **param, char **val) | |
166 | { | |
167 | unsigned int i, equals = 0; | |
168 | int in_quote = 0, quoted = 0; | |
169 | char *next; | |
170 | ||
171 | if (*args == '"') { | |
172 | args++; | |
173 | in_quote = 1; | |
174 | quoted = 1; | |
175 | } | |
176 | ||
177 | for (i = 0; args[i]; i++) { | |
178 | if (isspace(args[i]) && !in_quote) | |
179 | break; | |
180 | if (equals == 0) { | |
181 | if (args[i] == '=') | |
182 | equals = i; | |
183 | } | |
184 | if (args[i] == '"') | |
185 | in_quote = !in_quote; | |
186 | } | |
187 | ||
188 | *param = args; | |
189 | if (!equals) | |
190 | *val = NULL; | |
191 | else { | |
192 | args[equals] = '\0'; | |
193 | *val = args + equals + 1; | |
194 | ||
195 | /* Don't include quotes in value. */ | |
196 | if (**val == '"') { | |
197 | (*val)++; | |
198 | if (args[i-1] == '"') | |
199 | args[i-1] = '\0'; | |
200 | } | |
201 | } | |
202 | if (quoted && args[i-1] == '"') | |
203 | args[i-1] = '\0'; | |
204 | ||
205 | if (args[i]) { | |
206 | args[i] = '\0'; | |
207 | next = args + i + 1; | |
208 | } else | |
209 | next = args + i; | |
210 | ||
211 | /* Chew up trailing spaces. */ | |
212 | return skip_spaces(next); | |
213 | } | |
214 | ||
215 | /* Args looks like "foo=bar,bar2 baz=fuz wiz". */ | |
216 | char *parse_args(const char *doing, | |
217 | char *args, | |
218 | const struct kernel_param *params, | |
219 | unsigned num, | |
220 | s16 min_level, | |
221 | s16 max_level, | |
222 | void *arg, | |
223 | int (*unknown)(char *param, char *val, | |
224 | const char *doing, void *arg)) | |
225 | { | |
226 | char *param, *val; | |
227 | ||
228 | /* Chew leading spaces */ | |
229 | args = skip_spaces(args); | |
230 | ||
231 | if (*args) | |
232 | pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args); | |
233 | ||
234 | while (*args) { | |
235 | int ret; | |
236 | int irq_was_disabled; | |
237 | ||
238 | args = next_arg(args, ¶m, &val); | |
239 | /* Stop at -- */ | |
240 | if (!val && strcmp(param, "--") == 0) | |
241 | return args; | |
242 | irq_was_disabled = irqs_disabled(); | |
243 | ret = parse_one(param, val, doing, params, num, | |
244 | min_level, max_level, arg, unknown); | |
245 | if (irq_was_disabled && !irqs_disabled()) | |
246 | pr_warn("%s: option '%s' enabled irq's!\n", | |
247 | doing, param); | |
248 | ||
249 | switch (ret) { | |
250 | case -ENOENT: | |
251 | pr_err("%s: Unknown parameter `%s'\n", doing, param); | |
252 | return ERR_PTR(ret); | |
253 | case -ENOSPC: | |
254 | pr_err("%s: `%s' too large for parameter `%s'\n", | |
255 | doing, val ?: "", param); | |
256 | return ERR_PTR(ret); | |
257 | case 0: | |
258 | break; | |
259 | default: | |
260 | pr_err("%s: `%s' invalid for parameter `%s'\n", | |
261 | doing, val ?: "", param); | |
262 | return ERR_PTR(ret); | |
263 | } | |
264 | } | |
265 | ||
266 | /* All parsed OK. */ | |
267 | return NULL; | |
268 | } | |
269 | ||
270 | /* Lazy bastard, eh? */ | |
271 | #define STANDARD_PARAM_DEF(name, type, format, strtolfn) \ | |
272 | int param_set_##name(const char *val, const struct kernel_param *kp) \ | |
273 | { \ | |
274 | return strtolfn(val, 0, (type *)kp->arg); \ | |
275 | } \ | |
276 | int param_get_##name(char *buffer, const struct kernel_param *kp) \ | |
277 | { \ | |
278 | return scnprintf(buffer, PAGE_SIZE, format, \ | |
279 | *((type *)kp->arg)); \ | |
280 | } \ | |
281 | const struct kernel_param_ops param_ops_##name = { \ | |
282 | .set = param_set_##name, \ | |
283 | .get = param_get_##name, \ | |
284 | }; \ | |
285 | EXPORT_SYMBOL(param_set_##name); \ | |
286 | EXPORT_SYMBOL(param_get_##name); \ | |
287 | EXPORT_SYMBOL(param_ops_##name) | |
288 | ||
289 | ||
290 | STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8); | |
291 | STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16); | |
292 | STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16); | |
293 | STANDARD_PARAM_DEF(int, int, "%i", kstrtoint); | |
294 | STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint); | |
295 | STANDARD_PARAM_DEF(long, long, "%li", kstrtol); | |
296 | STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul); | |
297 | STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull); | |
298 | ||
299 | int param_set_charp(const char *val, const struct kernel_param *kp) | |
300 | { | |
301 | if (strlen(val) > 1024) { | |
302 | pr_err("%s: string parameter too long\n", kp->name); | |
303 | return -ENOSPC; | |
304 | } | |
305 | ||
306 | maybe_kfree_parameter(*(char **)kp->arg); | |
307 | ||
308 | /* This is a hack. We can't kmalloc in early boot, and we | |
309 | * don't need to; this mangled commandline is preserved. */ | |
310 | if (slab_is_available()) { | |
311 | *(char **)kp->arg = kmalloc_parameter(strlen(val)+1); | |
312 | if (!*(char **)kp->arg) | |
313 | return -ENOMEM; | |
314 | strcpy(*(char **)kp->arg, val); | |
315 | } else | |
316 | *(const char **)kp->arg = val; | |
317 | ||
318 | return 0; | |
319 | } | |
320 | EXPORT_SYMBOL(param_set_charp); | |
321 | ||
322 | int param_get_charp(char *buffer, const struct kernel_param *kp) | |
323 | { | |
324 | return scnprintf(buffer, PAGE_SIZE, "%s", *((char **)kp->arg)); | |
325 | } | |
326 | EXPORT_SYMBOL(param_get_charp); | |
327 | ||
328 | static void param_free_charp(void *arg) | |
329 | { | |
330 | maybe_kfree_parameter(*((char **)arg)); | |
331 | } | |
332 | ||
333 | const struct kernel_param_ops param_ops_charp = { | |
334 | .set = param_set_charp, | |
335 | .get = param_get_charp, | |
336 | .free = param_free_charp, | |
337 | }; | |
338 | EXPORT_SYMBOL(param_ops_charp); | |
339 | ||
340 | /* Actually could be a bool or an int, for historical reasons. */ | |
341 | int param_set_bool(const char *val, const struct kernel_param *kp) | |
342 | { | |
343 | /* No equals means "set"... */ | |
344 | if (!val) val = "1"; | |
345 | ||
346 | /* One of =[yYnN01] */ | |
347 | return strtobool(val, kp->arg); | |
348 | } | |
349 | EXPORT_SYMBOL(param_set_bool); | |
350 | ||
351 | int param_get_bool(char *buffer, const struct kernel_param *kp) | |
352 | { | |
353 | /* Y and N chosen as being relatively non-coder friendly */ | |
354 | return sprintf(buffer, "%c", *(bool *)kp->arg ? 'Y' : 'N'); | |
355 | } | |
356 | EXPORT_SYMBOL(param_get_bool); | |
357 | ||
358 | const struct kernel_param_ops param_ops_bool = { | |
359 | .flags = KERNEL_PARAM_OPS_FL_NOARG, | |
360 | .set = param_set_bool, | |
361 | .get = param_get_bool, | |
362 | }; | |
363 | EXPORT_SYMBOL(param_ops_bool); | |
364 | ||
365 | int param_set_bool_enable_only(const char *val, const struct kernel_param *kp) | |
366 | { | |
367 | int err = 0; | |
368 | bool new_value; | |
369 | bool orig_value = *(bool *)kp->arg; | |
370 | struct kernel_param dummy_kp = *kp; | |
371 | ||
372 | dummy_kp.arg = &new_value; | |
373 | ||
374 | err = param_set_bool(val, &dummy_kp); | |
375 | if (err) | |
376 | return err; | |
377 | ||
378 | /* Don't let them unset it once it's set! */ | |
379 | if (!new_value && orig_value) | |
380 | return -EROFS; | |
381 | ||
382 | if (new_value) | |
383 | err = param_set_bool(val, kp); | |
384 | ||
385 | return err; | |
386 | } | |
387 | EXPORT_SYMBOL_GPL(param_set_bool_enable_only); | |
388 | ||
389 | const struct kernel_param_ops param_ops_bool_enable_only = { | |
390 | .flags = KERNEL_PARAM_OPS_FL_NOARG, | |
391 | .set = param_set_bool_enable_only, | |
392 | .get = param_get_bool, | |
393 | }; | |
394 | EXPORT_SYMBOL_GPL(param_ops_bool_enable_only); | |
395 | ||
396 | /* This one must be bool. */ | |
397 | int param_set_invbool(const char *val, const struct kernel_param *kp) | |
398 | { | |
399 | int ret; | |
400 | bool boolval; | |
401 | struct kernel_param dummy; | |
402 | ||
403 | dummy.arg = &boolval; | |
404 | ret = param_set_bool(val, &dummy); | |
405 | if (ret == 0) | |
406 | *(bool *)kp->arg = !boolval; | |
407 | return ret; | |
408 | } | |
409 | EXPORT_SYMBOL(param_set_invbool); | |
410 | ||
411 | int param_get_invbool(char *buffer, const struct kernel_param *kp) | |
412 | { | |
413 | return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y'); | |
414 | } | |
415 | EXPORT_SYMBOL(param_get_invbool); | |
416 | ||
417 | const struct kernel_param_ops param_ops_invbool = { | |
418 | .set = param_set_invbool, | |
419 | .get = param_get_invbool, | |
420 | }; | |
421 | EXPORT_SYMBOL(param_ops_invbool); | |
422 | ||
423 | int param_set_bint(const char *val, const struct kernel_param *kp) | |
424 | { | |
425 | /* Match bool exactly, by re-using it. */ | |
426 | struct kernel_param boolkp = *kp; | |
427 | bool v; | |
428 | int ret; | |
429 | ||
430 | boolkp.arg = &v; | |
431 | ||
432 | ret = param_set_bool(val, &boolkp); | |
433 | if (ret == 0) | |
434 | *(int *)kp->arg = v; | |
435 | return ret; | |
436 | } | |
437 | EXPORT_SYMBOL(param_set_bint); | |
438 | ||
439 | const struct kernel_param_ops param_ops_bint = { | |
440 | .flags = KERNEL_PARAM_OPS_FL_NOARG, | |
441 | .set = param_set_bint, | |
442 | .get = param_get_int, | |
443 | }; | |
444 | EXPORT_SYMBOL(param_ops_bint); | |
445 | ||
446 | /* We break the rule and mangle the string. */ | |
447 | static int param_array(struct module *mod, | |
448 | const char *name, | |
449 | const char *val, | |
450 | unsigned int min, unsigned int max, | |
451 | void *elem, int elemsize, | |
452 | int (*set)(const char *, const struct kernel_param *kp), | |
453 | s16 level, | |
454 | unsigned int *num) | |
455 | { | |
456 | int ret; | |
457 | struct kernel_param kp; | |
458 | char save; | |
459 | ||
460 | /* Get the name right for errors. */ | |
461 | kp.name = name; | |
462 | kp.arg = elem; | |
463 | kp.level = level; | |
464 | ||
465 | *num = 0; | |
466 | /* We expect a comma-separated list of values. */ | |
467 | do { | |
468 | int len; | |
469 | ||
470 | if (*num == max) { | |
471 | pr_err("%s: can only take %i arguments\n", name, max); | |
472 | return -EINVAL; | |
473 | } | |
474 | len = strcspn(val, ","); | |
475 | ||
476 | /* nul-terminate and parse */ | |
477 | save = val[len]; | |
478 | ((char *)val)[len] = '\0'; | |
479 | check_kparam_locked(mod); | |
480 | ret = set(val, &kp); | |
481 | ||
482 | if (ret != 0) | |
483 | return ret; | |
484 | kp.arg += elemsize; | |
485 | val += len+1; | |
486 | (*num)++; | |
487 | } while (save == ','); | |
488 | ||
489 | if (*num < min) { | |
490 | pr_err("%s: needs at least %i arguments\n", name, min); | |
491 | return -EINVAL; | |
492 | } | |
493 | return 0; | |
494 | } | |
495 | ||
496 | static int param_array_set(const char *val, const struct kernel_param *kp) | |
497 | { | |
498 | const struct kparam_array *arr = kp->arr; | |
499 | unsigned int temp_num; | |
500 | ||
501 | return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem, | |
502 | arr->elemsize, arr->ops->set, kp->level, | |
503 | arr->num ?: &temp_num); | |
504 | } | |
505 | ||
506 | static int param_array_get(char *buffer, const struct kernel_param *kp) | |
507 | { | |
508 | int i, off, ret; | |
509 | const struct kparam_array *arr = kp->arr; | |
510 | struct kernel_param p = *kp; | |
511 | ||
512 | for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) { | |
513 | if (i) | |
514 | buffer[off++] = ','; | |
515 | p.arg = arr->elem + arr->elemsize * i; | |
516 | check_kparam_locked(p.mod); | |
517 | ret = arr->ops->get(buffer + off, &p); | |
518 | if (ret < 0) | |
519 | return ret; | |
520 | off += ret; | |
521 | } | |
522 | buffer[off] = '\0'; | |
523 | return off; | |
524 | } | |
525 | ||
526 | static void param_array_free(void *arg) | |
527 | { | |
528 | unsigned int i; | |
529 | const struct kparam_array *arr = arg; | |
530 | ||
531 | if (arr->ops->free) | |
532 | for (i = 0; i < (arr->num ? *arr->num : arr->max); i++) | |
533 | arr->ops->free(arr->elem + arr->elemsize * i); | |
534 | } | |
535 | ||
536 | const struct kernel_param_ops param_array_ops = { | |
537 | .set = param_array_set, | |
538 | .get = param_array_get, | |
539 | .free = param_array_free, | |
540 | }; | |
541 | EXPORT_SYMBOL(param_array_ops); | |
542 | ||
543 | int param_set_copystring(const char *val, const struct kernel_param *kp) | |
544 | { | |
545 | const struct kparam_string *kps = kp->str; | |
546 | ||
547 | if (strlen(val)+1 > kps->maxlen) { | |
548 | pr_err("%s: string doesn't fit in %u chars.\n", | |
549 | kp->name, kps->maxlen-1); | |
550 | return -ENOSPC; | |
551 | } | |
552 | strcpy(kps->string, val); | |
553 | return 0; | |
554 | } | |
555 | EXPORT_SYMBOL(param_set_copystring); | |
556 | ||
557 | int param_get_string(char *buffer, const struct kernel_param *kp) | |
558 | { | |
559 | const struct kparam_string *kps = kp->str; | |
560 | return strlcpy(buffer, kps->string, kps->maxlen); | |
561 | } | |
562 | EXPORT_SYMBOL(param_get_string); | |
563 | ||
564 | const struct kernel_param_ops param_ops_string = { | |
565 | .set = param_set_copystring, | |
566 | .get = param_get_string, | |
567 | }; | |
568 | EXPORT_SYMBOL(param_ops_string); | |
569 | ||
570 | /* sysfs output in /sys/modules/XYZ/parameters/ */ | |
571 | #define to_module_attr(n) container_of(n, struct module_attribute, attr) | |
572 | #define to_module_kobject(n) container_of(n, struct module_kobject, kobj) | |
573 | ||
574 | struct param_attribute | |
575 | { | |
576 | struct module_attribute mattr; | |
577 | const struct kernel_param *param; | |
578 | }; | |
579 | ||
580 | struct module_param_attrs | |
581 | { | |
582 | unsigned int num; | |
583 | struct attribute_group grp; | |
584 | struct param_attribute attrs[0]; | |
585 | }; | |
586 | ||
587 | #ifdef CONFIG_SYSFS | |
588 | #define to_param_attr(n) container_of(n, struct param_attribute, mattr) | |
589 | ||
590 | static ssize_t param_attr_show(struct module_attribute *mattr, | |
591 | struct module_kobject *mk, char *buf) | |
592 | { | |
593 | int count; | |
594 | struct param_attribute *attribute = to_param_attr(mattr); | |
595 | ||
596 | if (!attribute->param->ops->get) | |
597 | return -EPERM; | |
598 | ||
599 | kernel_param_lock(mk->mod); | |
600 | count = attribute->param->ops->get(buf, attribute->param); | |
601 | kernel_param_unlock(mk->mod); | |
602 | if (count > 0) { | |
603 | strcat(buf, "\n"); | |
604 | ++count; | |
605 | } | |
606 | return count; | |
607 | } | |
608 | ||
609 | /* sysfs always hands a nul-terminated string in buf. We rely on that. */ | |
610 | static ssize_t param_attr_store(struct module_attribute *mattr, | |
611 | struct module_kobject *mk, | |
612 | const char *buf, size_t len) | |
613 | { | |
614 | int err; | |
615 | struct param_attribute *attribute = to_param_attr(mattr); | |
616 | ||
617 | if (!attribute->param->ops->set) | |
618 | return -EPERM; | |
619 | ||
620 | kernel_param_lock(mk->mod); | |
621 | param_check_unsafe(attribute->param); | |
622 | err = attribute->param->ops->set(buf, attribute->param); | |
623 | kernel_param_unlock(mk->mod); | |
624 | if (!err) | |
625 | return len; | |
626 | return err; | |
627 | } | |
628 | #endif | |
629 | ||
630 | #ifdef CONFIG_MODULES | |
631 | #define __modinit | |
632 | #else | |
633 | #define __modinit __init | |
634 | #endif | |
635 | ||
636 | #ifdef CONFIG_SYSFS | |
637 | void kernel_param_lock(struct module *mod) | |
638 | { | |
639 | mutex_lock(KPARAM_MUTEX(mod)); | |
640 | } | |
641 | ||
642 | void kernel_param_unlock(struct module *mod) | |
643 | { | |
644 | mutex_unlock(KPARAM_MUTEX(mod)); | |
645 | } | |
646 | ||
647 | EXPORT_SYMBOL(kernel_param_lock); | |
648 | EXPORT_SYMBOL(kernel_param_unlock); | |
649 | ||
650 | /* | |
651 | * add_sysfs_param - add a parameter to sysfs | |
652 | * @mk: struct module_kobject | |
653 | * @kparam: the actual parameter definition to add to sysfs | |
654 | * @name: name of parameter | |
655 | * | |
656 | * Create a kobject if for a (per-module) parameter if mp NULL, and | |
657 | * create file in sysfs. Returns an error on out of memory. Always cleans up | |
658 | * if there's an error. | |
659 | */ | |
660 | static __modinit int add_sysfs_param(struct module_kobject *mk, | |
661 | const struct kernel_param *kp, | |
662 | const char *name) | |
663 | { | |
664 | struct module_param_attrs *new_mp; | |
665 | struct attribute **new_attrs; | |
666 | unsigned int i; | |
667 | ||
668 | /* We don't bother calling this with invisible parameters. */ | |
669 | BUG_ON(!kp->perm); | |
670 | ||
671 | if (!mk->mp) { | |
672 | /* First allocation. */ | |
673 | mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL); | |
674 | if (!mk->mp) | |
675 | return -ENOMEM; | |
676 | mk->mp->grp.name = "parameters"; | |
677 | /* NULL-terminated attribute array. */ | |
678 | mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]), | |
679 | GFP_KERNEL); | |
680 | /* Caller will cleanup via free_module_param_attrs */ | |
681 | if (!mk->mp->grp.attrs) | |
682 | return -ENOMEM; | |
683 | } | |
684 | ||
685 | /* Enlarge allocations. */ | |
686 | new_mp = krealloc(mk->mp, | |
687 | sizeof(*mk->mp) + | |
688 | sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1), | |
689 | GFP_KERNEL); | |
690 | if (!new_mp) | |
691 | return -ENOMEM; | |
692 | mk->mp = new_mp; | |
693 | ||
694 | /* Extra pointer for NULL terminator */ | |
695 | new_attrs = krealloc(mk->mp->grp.attrs, | |
696 | sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2), | |
697 | GFP_KERNEL); | |
698 | if (!new_attrs) | |
699 | return -ENOMEM; | |
700 | mk->mp->grp.attrs = new_attrs; | |
701 | ||
702 | /* Tack new one on the end. */ | |
703 | memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0])); | |
704 | sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr); | |
705 | mk->mp->attrs[mk->mp->num].param = kp; | |
706 | mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show; | |
707 | /* Do not allow runtime DAC changes to make param writable. */ | |
708 | if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0) | |
709 | mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store; | |
710 | else | |
711 | mk->mp->attrs[mk->mp->num].mattr.store = NULL; | |
712 | mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name; | |
713 | mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm; | |
714 | mk->mp->num++; | |
715 | ||
716 | /* Fix up all the pointers, since krealloc can move us */ | |
717 | for (i = 0; i < mk->mp->num; i++) | |
718 | mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr; | |
719 | mk->mp->grp.attrs[mk->mp->num] = NULL; | |
720 | return 0; | |
721 | } | |
722 | ||
723 | #ifdef CONFIG_MODULES | |
724 | static void free_module_param_attrs(struct module_kobject *mk) | |
725 | { | |
726 | if (mk->mp) | |
727 | kfree(mk->mp->grp.attrs); | |
728 | kfree(mk->mp); | |
729 | mk->mp = NULL; | |
730 | } | |
731 | ||
732 | /* | |
733 | * module_param_sysfs_setup - setup sysfs support for one module | |
734 | * @mod: module | |
735 | * @kparam: module parameters (array) | |
736 | * @num_params: number of module parameters | |
737 | * | |
738 | * Adds sysfs entries for module parameters under | |
739 | * /sys/module/[mod->name]/parameters/ | |
740 | */ | |
741 | int module_param_sysfs_setup(struct module *mod, | |
742 | const struct kernel_param *kparam, | |
743 | unsigned int num_params) | |
744 | { | |
745 | int i, err; | |
746 | bool params = false; | |
747 | ||
748 | for (i = 0; i < num_params; i++) { | |
749 | if (kparam[i].perm == 0) | |
750 | continue; | |
751 | err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name); | |
752 | if (err) { | |
753 | free_module_param_attrs(&mod->mkobj); | |
754 | return err; | |
755 | } | |
756 | params = true; | |
757 | } | |
758 | ||
759 | if (!params) | |
760 | return 0; | |
761 | ||
762 | /* Create the param group. */ | |
763 | err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); | |
764 | if (err) | |
765 | free_module_param_attrs(&mod->mkobj); | |
766 | return err; | |
767 | } | |
768 | ||
769 | /* | |
770 | * module_param_sysfs_remove - remove sysfs support for one module | |
771 | * @mod: module | |
772 | * | |
773 | * Remove sysfs entries for module parameters and the corresponding | |
774 | * kobject. | |
775 | */ | |
776 | void module_param_sysfs_remove(struct module *mod) | |
777 | { | |
778 | if (mod->mkobj.mp) { | |
779 | sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); | |
780 | /* We are positive that no one is using any param | |
781 | * attrs at this point. Deallocate immediately. */ | |
782 | free_module_param_attrs(&mod->mkobj); | |
783 | } | |
784 | } | |
785 | #endif | |
786 | ||
787 | void destroy_params(const struct kernel_param *params, unsigned num) | |
788 | { | |
789 | unsigned int i; | |
790 | ||
791 | for (i = 0; i < num; i++) | |
792 | if (params[i].ops->free) | |
793 | params[i].ops->free(params[i].arg); | |
794 | } | |
795 | ||
796 | static struct module_kobject * __init locate_module_kobject(const char *name) | |
797 | { | |
798 | struct module_kobject *mk; | |
799 | struct kobject *kobj; | |
800 | int err; | |
801 | ||
802 | kobj = kset_find_obj(module_kset, name); | |
803 | if (kobj) { | |
804 | mk = to_module_kobject(kobj); | |
805 | } else { | |
806 | mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL); | |
807 | BUG_ON(!mk); | |
808 | ||
809 | mk->mod = THIS_MODULE; | |
810 | mk->kobj.kset = module_kset; | |
811 | err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, | |
812 | "%s", name); | |
813 | #ifdef CONFIG_MODULES | |
814 | if (!err) | |
815 | err = sysfs_create_file(&mk->kobj, &module_uevent.attr); | |
816 | #endif | |
817 | if (err) { | |
818 | kobject_put(&mk->kobj); | |
819 | pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n", | |
820 | name, err); | |
821 | return NULL; | |
822 | } | |
823 | ||
824 | /* So that we hold reference in both cases. */ | |
825 | kobject_get(&mk->kobj); | |
826 | } | |
827 | ||
828 | return mk; | |
829 | } | |
830 | ||
831 | static void __init kernel_add_sysfs_param(const char *name, | |
832 | const struct kernel_param *kparam, | |
833 | unsigned int name_skip) | |
834 | { | |
835 | struct module_kobject *mk; | |
836 | int err; | |
837 | ||
838 | mk = locate_module_kobject(name); | |
839 | if (!mk) | |
840 | return; | |
841 | ||
842 | /* We need to remove old parameters before adding more. */ | |
843 | if (mk->mp) | |
844 | sysfs_remove_group(&mk->kobj, &mk->mp->grp); | |
845 | ||
846 | /* These should not fail at boot. */ | |
847 | err = add_sysfs_param(mk, kparam, kparam->name + name_skip); | |
848 | BUG_ON(err); | |
849 | err = sysfs_create_group(&mk->kobj, &mk->mp->grp); | |
850 | BUG_ON(err); | |
851 | kobject_uevent(&mk->kobj, KOBJ_ADD); | |
852 | kobject_put(&mk->kobj); | |
853 | } | |
854 | ||
855 | /* | |
856 | * param_sysfs_builtin - add sysfs parameters for built-in modules | |
857 | * | |
858 | * Add module_parameters to sysfs for "modules" built into the kernel. | |
859 | * | |
860 | * The "module" name (KBUILD_MODNAME) is stored before a dot, the | |
861 | * "parameter" name is stored behind a dot in kernel_param->name. So, | |
862 | * extract the "module" name for all built-in kernel_param-eters, | |
863 | * and for all who have the same, call kernel_add_sysfs_param. | |
864 | */ | |
865 | static void __init param_sysfs_builtin(void) | |
866 | { | |
867 | const struct kernel_param *kp; | |
868 | unsigned int name_len; | |
869 | char modname[MODULE_NAME_LEN]; | |
870 | ||
871 | for (kp = __start___param; kp < __stop___param; kp++) { | |
872 | char *dot; | |
873 | ||
874 | if (kp->perm == 0) | |
875 | continue; | |
876 | ||
877 | dot = strchr(kp->name, '.'); | |
878 | if (!dot) { | |
879 | /* This happens for core_param() */ | |
880 | strcpy(modname, "kernel"); | |
881 | name_len = 0; | |
882 | } else { | |
883 | name_len = dot - kp->name + 1; | |
884 | strlcpy(modname, kp->name, name_len); | |
885 | } | |
886 | kernel_add_sysfs_param(modname, kp, name_len); | |
887 | } | |
888 | } | |
889 | ||
890 | ssize_t __modver_version_show(struct module_attribute *mattr, | |
891 | struct module_kobject *mk, char *buf) | |
892 | { | |
893 | struct module_version_attribute *vattr = | |
894 | container_of(mattr, struct module_version_attribute, mattr); | |
895 | ||
896 | return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version); | |
897 | } | |
898 | ||
899 | extern const struct module_version_attribute *__start___modver[]; | |
900 | extern const struct module_version_attribute *__stop___modver[]; | |
901 | ||
902 | static void __init version_sysfs_builtin(void) | |
903 | { | |
904 | const struct module_version_attribute **p; | |
905 | struct module_kobject *mk; | |
906 | int err; | |
907 | ||
908 | for (p = __start___modver; p < __stop___modver; p++) { | |
909 | const struct module_version_attribute *vattr = *p; | |
910 | ||
911 | mk = locate_module_kobject(vattr->module_name); | |
912 | if (mk) { | |
913 | err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr); | |
914 | WARN_ON_ONCE(err); | |
915 | kobject_uevent(&mk->kobj, KOBJ_ADD); | |
916 | kobject_put(&mk->kobj); | |
917 | } | |
918 | } | |
919 | } | |
920 | ||
921 | /* module-related sysfs stuff */ | |
922 | ||
923 | static ssize_t module_attr_show(struct kobject *kobj, | |
924 | struct attribute *attr, | |
925 | char *buf) | |
926 | { | |
927 | struct module_attribute *attribute; | |
928 | struct module_kobject *mk; | |
929 | int ret; | |
930 | ||
931 | attribute = to_module_attr(attr); | |
932 | mk = to_module_kobject(kobj); | |
933 | ||
934 | if (!attribute->show) | |
935 | return -EIO; | |
936 | ||
937 | ret = attribute->show(attribute, mk, buf); | |
938 | ||
939 | return ret; | |
940 | } | |
941 | ||
942 | static ssize_t module_attr_store(struct kobject *kobj, | |
943 | struct attribute *attr, | |
944 | const char *buf, size_t len) | |
945 | { | |
946 | struct module_attribute *attribute; | |
947 | struct module_kobject *mk; | |
948 | int ret; | |
949 | ||
950 | attribute = to_module_attr(attr); | |
951 | mk = to_module_kobject(kobj); | |
952 | ||
953 | if (!attribute->store) | |
954 | return -EIO; | |
955 | ||
956 | ret = attribute->store(attribute, mk, buf, len); | |
957 | ||
958 | return ret; | |
959 | } | |
960 | ||
961 | static const struct sysfs_ops module_sysfs_ops = { | |
962 | .show = module_attr_show, | |
963 | .store = module_attr_store, | |
964 | }; | |
965 | ||
966 | static int uevent_filter(struct kset *kset, struct kobject *kobj) | |
967 | { | |
968 | struct kobj_type *ktype = get_ktype(kobj); | |
969 | ||
970 | if (ktype == &module_ktype) | |
971 | return 1; | |
972 | return 0; | |
973 | } | |
974 | ||
975 | static const struct kset_uevent_ops module_uevent_ops = { | |
976 | .filter = uevent_filter, | |
977 | }; | |
978 | ||
979 | struct kset *module_kset; | |
980 | int module_sysfs_initialized; | |
981 | ||
982 | static void module_kobj_release(struct kobject *kobj) | |
983 | { | |
984 | struct module_kobject *mk = to_module_kobject(kobj); | |
985 | complete(mk->kobj_completion); | |
986 | } | |
987 | ||
988 | struct kobj_type module_ktype = { | |
989 | .release = module_kobj_release, | |
990 | .sysfs_ops = &module_sysfs_ops, | |
991 | }; | |
992 | ||
993 | /* | |
994 | * param_sysfs_init - wrapper for built-in params support | |
995 | */ | |
996 | static int __init param_sysfs_init(void) | |
997 | { | |
998 | module_kset = kset_create_and_add("module", &module_uevent_ops, NULL); | |
999 | if (!module_kset) { | |
1000 | printk(KERN_WARNING "%s (%d): error creating kset\n", | |
1001 | __FILE__, __LINE__); | |
1002 | return -ENOMEM; | |
1003 | } | |
1004 | module_sysfs_initialized = 1; | |
1005 | ||
1006 | version_sysfs_builtin(); | |
1007 | param_sysfs_builtin(); | |
1008 | ||
1009 | return 0; | |
1010 | } | |
1011 | subsys_initcall(param_sysfs_init); | |
1012 | ||
1013 | #endif /* CONFIG_SYSFS */ |